Crashed North Dakota air ambulance didn't send distress call

This Monday, Nov. 19, 2018, photo provided by the Morton County Sheriff's Office shows the wreckage of a twin-engine Bismarck Air Medical airplane that crashed late Sunday, Nov. 18 about 20 miles northwest of Bismarck, N.D., killing all three on board. (Morton County Sheriff's Office via AP)

BISMARCK, N.D. – An air ambulance that crashed in western North Dakota this month and killed all three people on board did not send out a distress call before it apparently broke apart in midair.

What caused the breakup is still a mystery, but there's no indication that the Cessna 441 turboprop airplane was struck by anything and there was no fire on board. Weather also is not believed to have been a factor, Morton County Sheriff Kyle Kirchmeier told The Bismarck Tribune.

"It's in NTSB's ballpark to find out how and why and what caused that," Kirchmeier said of the National Transportation Safety Board, which handles such investigations. They typically take months to complete.

The Nov. 18 Bismarck Air Medical crash northwest of Bismarck killed 48-year-old pilot Todd Lasky and 63-year-old nurse Bonnie Cook, both of Bismarck, and 47-year-old paramedic Chris Iverson, of Mandan. They were on their way to Williston to pick up a patient. There were no survivors.

"There was no indication of any issues on the plane or a distress call made before the plane went missing," Kirchmeier said.

The NTSB's preliminary report on the crash , released Thursday, said radar indicated the airplane climbed to 14,000 feet, then entered a steep right bank and disappeared from radar.

Preliminary reports from the state medical examiner indicate the crew members died from blunt force trauma injuries.

The Civil Air Patrol said an initial analysis by an Air Force rescue center showed the plane might have broken up in midair. Authorities said the scattered debris field backs up that theory.

Wreckage was scattered over an area 1 mile (1.61 kilometers) long and 600 feet (182.88 meters) wide, according to the NTSB report. The cockpit, cabin, engines, propellers, tail area and wings were recovered.

NTSB spokesman Keith Holloway said he doesn't think the plane had a flight data recorder.